611.3d

Continuous effects from static abilities may allow a player to play a land or cast a permanent spell, or may grant an ability to a permanent spell or card that allows it to be cast. If the effect also grants that object an ability that functions only on the battlefield, that ability lasts as long as stated by the effect granting that permission or ability. If no duration is stated, it lasts until the end of the game. This is an exception to rules 611.3a–b.